include/linux/netfilter/nfnetlink.h

   1 #ifndef _NFNETLINK_H
   2 #define _NFNETLINK_H
   3
   4
   5 #include <linux/netlink.h>
   6 #include <linux/capability.h>
   7 #include <net/netlink.h>
   8 #include <uapi/linux/netfilter/nfnetlink.h>
   9
  10 struct nfnl_callback {
  11         int (*call)(struct net *net, struct sock *nl, struct sk_buff *skb,
  12                     const struct nlmsghdr *nlh,
  13                     const struct nlattr * const cda[]);
  14         int (*call_rcu)(struct net *net, struct sock *nl, struct sk_buff *skb,
  15                         const struct nlmsghdr *nlh,
  16                         const struct nlattr * const cda[]);
  17         int (*call_batch)(struct net *net, struct sock *nl, struct sk_buff *skb,
  18                           const struct nlmsghdr *nlh,
  19                           const struct nlattr * const cda[]);
  20         const struct nla_policy *policy;        /* netlink attribute policy */
  21         const u_int16_t attr_count;             /* number of nlattr's */
  22 };
  23
  24 struct nfnetlink_subsystem {
  25         const char *name;
  26         __u8 subsys_id;                 /* nfnetlink subsystem ID */
  27         __u8 cb_count;                  /* number of callbacks */
  28         const struct nfnl_callback *cb; /* callback for individual types */
  29         int (*commit)(struct net *net, struct sk_buff *skb);
  30         int (*abort)(struct net *net, struct sk_buff *skb);
  31 };
  32
  33 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
  34 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
  35
  36 int nfnetlink_has_listeners(struct net *net, unsigned int group);
  37 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
  38                    unsigned int group, int echo, gfp_t flags);
  39 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
  40 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
  41                       int flags);
  42
  43 void nfnl_lock(__u8 subsys_id);
  44 void nfnl_unlock(__u8 subsys_id);
  45 #ifdef CONFIG_PROVE_LOCKING
  46 bool lockdep_nfnl_is_held(__u8 subsys_id);
  47 #else
  48 static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
  49 {
  50         return true;
  51 }
  52 #endif /* CONFIG_PROVE_LOCKING */
  53
  54 /*
  55  * nfnl_dereference - fetch RCU pointer when updates are prevented by subsys mutex
  56  *
  57  * @p: The pointer to read, prior to dereferencing
  58  * @ss: The nfnetlink subsystem ID
  59  *
  60  * Return the value of the specified RCU-protected pointer, but omit
  61  * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
  62  * caller holds the NFNL subsystem mutex.
  63  */
  64 #define nfnl_dereference(p, ss)                                 \
  65         rcu_dereference_protected(p, lockdep_nfnl_is_held(ss))
  66
  67 #define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
  68         MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
  69
  70 #endif  /* _NFNETLINK_H */